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samd21: Basic implementation of spi_acquire(), spi_release()

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Signed-off-by: Joakim Gebart <joakim.gebart@eistec.se>
This commit is contained in:
Joakim Gebart 2015-01-16 13:38:01 +01:00
parent b20f21f2c5
commit bec43f11d8
1 changed files with 39 additions and 3 deletions
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42
cpu/samd21/periph/spi.c
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@ -14,12 +14,15 @@
* @brief Low-level SPI driver implementation * @brief Low-level SPI driver implementation
* *
* @author Thomas Eichinger <thomas.eichinger@fu-berlin.de> * @author Thomas Eichinger <thomas.eichinger@fu-berlin.de>
* Troels Hoffmeyer <troels.d.hoffmeyer@gmail.com> * @author Troels Hoffmeyer <troels.d.hoffmeyer@gmail.com>
* @author Hauke Petersen <hauke.petersen@fu-berlin.de>
* @author Joakim Gebart <joakim.gebart@eistec.se>
* *
* @} * @}
*/ */
#include "cpu.h" #include "cpu.h"
#include "mutex.h"
#include "periph/gpio.h" #include "periph/gpio.h"
#include "periph/spi.h" #include "periph/spi.h"
#include "periph_conf.h" #include "periph_conf.h"
@ -28,6 +31,21 @@
#include "debug.h" #include "debug.h"
#if SPI_0_EN || SPI_1_EN #if SPI_0_EN || SPI_1_EN
/**
* @brief Array holding one pre-initialized mutex for each SPI device
*/
static mutex_t locks[] = {
#if SPI_0_EN
[SPI_0] = MUTEX_INIT,
#endif
#if SPI_1_EN
[SPI_1] = MUTEX_INIT,
#endif
#if SPI_2_EN
[SPI_2] = MUTEX_INIT
#endif
};
int spi_init_master(spi_t dev, spi_conf_t conf, spi_speed_t speed) int spi_init_master(spi_t dev, spi_conf_t conf, spi_speed_t speed)
{ {
SercomSpi* spi_dev = 0; SercomSpi* spi_dev = 0;
@ -80,7 +98,7 @@ int spi_init_master(spi_t dev, spi_conf_t conf, spi_speed_t speed)
/* Enable sercom4 in power manager */ /* Enable sercom4 in power manager */
PM->APBCMASK.reg |= PM_APBCMASK_SERCOM4; PM->APBCMASK.reg |= PM_APBCMASK_SERCOM4;
GCLK->CLKCTRL.reg = (uint32_t)((GCLK_CLKCTRL_CLKEN GCLK->CLKCTRL.reg = (uint32_t)((GCLK_CLKCTRL_CLKEN
| GCLK_CLKCTRL_GEN_GCLK0 | GCLK_CLKCTRL_GEN_GCLK0
| (SERCOM4_GCLK_ID_CORE << GCLK_CLKCTRL_ID_Pos))); | (SERCOM4_GCLK_ID_CORE << GCLK_CLKCTRL_ID_Pos)));
/* Setup clock */ /* Setup clock */
@ -174,7 +192,25 @@ int spi_init_slave(spi_t dev, spi_conf_t conf, char (*cb)(char))
} }
void spi_transmission_begin(spi_t dev, char reset_val) void spi_transmission_begin(spi_t dev, char reset_val)
{ {
/* TODO*/ /* TODO*/
}
int spi_acquire(spi_t dev)
{
if (dev >= SPI_NUMOF) {
return -1;
}
mutex_lock(&locks[dev]);
return 0;
}
int spi_release(spi_t dev)
{
if (dev >= SPI_NUMOF) {
return -1;
}
mutex_unlock(&locks[dev]);
return 0;
} }
int spi_transfer_byte(spi_t dev, char out, char *in) int spi_transfer_byte(spi_t dev, char out, char *in)